Byzantine Fault Tolerance in Long-Lived Systems

This paper proposes counter-measures that can be deployedas part of a replicated system to reduce the size ofW, and thus reduce the class of attacks to which the system is vulnerable. Obviously it will not be possible to withstandall attacks via this technique, in particular attacks with verysmall A. But we will propose techniques that can reduceWto quite a small value.In the remainder of this paper, we discuss how to lowerthe value of W. We begin by discussing attacks. Then wediscuss some prior work in this area and why it is insufficient.The final section describes the approach we propose.